Lipids

1. Lipids More types of lipids…

2. Waxes: esters of saturated fatty acids and a long-chain alcohol; each with 14-30 carbons • Where are they found? • Many plant and animals • Coatings on fruits, leaves and stems of plants help prevent water loss and damage from pests • Animals have wax on the skin, fur and feathers for water-proofing Waxes

3. Beeswax • Found in honeycomb • Used for candles, shoe polish, wax paper • Carnauba wax • Found in palm trees • Used for furniture, cars, floors, shoes • Jojoba wax • Found in jojoba plants • Used for candles, soaps and cosmetics 3 known types of waxes

4. Fats and oils in the body are stored as triacyclycerols, also called triglycerides • Made up of a triester of glycerol and three fatty acids • Major form of energy storage for animals • Especially in animals that hibernate • Animals eat large quantities of plants, seeds and nuts with lots of fats and oils • This fat storage is the only source of energy Fats and Oils

5. Fats • A triacylclycerol that is solid at room temperature • Examples: meat, whole milk, butter, cheese • Commonly from animal sources • Oils • A triacylclycerol that is liquid at room temperature • Examples: corn, safflower, sunflower oil • Examples of solid oils: coconut, palm oil • Solids b/c mostly saturated fatty acids • Commonly from plant sources Fats vs. Oils

6. A family of lipids similar to triacylglycerols except instead of three fatty acids, contain a phosphate and amino alcohol group • Where are they found? • brain and nerve tissues • important in cell membranes for cellular permeability • make up the myelin sheath that protects nerve cells • egg yolks • yeast Glycerophospholipids

7. Compounds with a steroid nucleus (3 cyclohexane rings and one cyclopentane ring fused together) • Examples: • cholesterol • steroid hormones Steroids

8. One of the most important and abundant steroids in the body • Where is it in the body? • Cellular membranes • Myelin sheath • Brain and nerve tissues • Liver • Skin Cholesterol

9. How to you get cholesterol? • Eating meats, milk, eggs • The liver extracts it from fats, carbs and proteins • NONE is found in vegetables or plants Cholesterol

10. Too much cholesterol can lead to… • Gallstones in the gallbladder • Plaque/lipid build-up in the arteries • Increased risk of heart disease Cholesterol Dangers

11. LDL – low-density lipoprotein • “bad” cholesterol • Transport cholesterol to tissues for synthesis of cell membranes, steroid hormones and bile salts • When too much LDL, they deposit cholesterol in the arteries Different Types of Cholesterol

12. HDL – high-density lipoprotein • “good” cholesterol • Remove excess cholesterol from tissues and carry it to the liver to become bile salts and eliminated • Who has higher HDL levels? • Those who exercise regularly and eat less saturated fat! Different Types of Cholesterol

13. Chemical messengers • Sex hormones and adrenocortical hormones • testosterone and androsterone • Promote growth of muscle and facial hair • Promote maturation of the male sex organs and sperm • estrogens and progesterone • Female sex hormones • Help in development of the uterus, breasts • Progesterone prepares the uterus for the implantation of a fertilized eggs Steroid Hormones

14. Adrenal glands are located on the top of the kidney • Aldosterone: responsible for electrolyte and water balance • Cortisone: increases the blood glucose level and synthesis of glycogen • Prednisone: synthetic; medially used for reducing inflammation and treating asthma and rheumatoid arthritis Adrenal Corticosteroids